2blue
Journeyman Pro
Despite what we know of him that is an assumption too far & would be difficult to support. However it is likely to be our next position.Surely the reason for the player not returning the card is because it was not a good round and such a score submitted would give him a change to his Handicap. Is he in fact Handicapping protecting by avoiding increases.
As per Rulefan rule 7 is your friend. Specifically
l If the Handicap Committee concludes that a player failed to submit a score
for the purpose of gaining an unfair advantage, it should consider
withdrawing the player’s Handicap Index, and/or applying an appropriate
penalty score (high or low depending on intent).
there is also a flow chart to follow.